Grinding mill



April 8, 1924.

W. G. BURNS ET AL GRINDING MILL Filed Sept. 15. 1923 ATTORNEY Patented Apr. 8, i924.

nira eras WILLIAM G. BURNS, OF NEW YORK, AND GEORGE C. HERE, 0]? FLUSHHTG, NEW YORK,

ASSIGNORS-TO JABEZ BURNS & SONS OF NEW 3:.

NEW YORK.

, N. Y., A CORPORATION OF GRINDING MILL Application filed September 13, 1923. Serial No. 662,370.

T 0 all whom it may concern-.2

Be it known that we, \VILLIAM G. BURNS and GEORGE C. Hnnz, both citizens of the United States, and residents of New York, county of New York, State of New York, and Flushing, Long island, in the county of Queens and State of New York, respectively, have invented certain new and useful Improvement in Grinding, Mills, of which the following is a specification.

This invention relates to grinding mills, and has for-its object 'to provide an improved grinding adjustment indicating means whereby an adjustment once obtained for a desired fineness of grind, such as of coffee, can be definitely reproduced in a new machine, or in the same machine upon reassembling after cleaning, sharpening, adjustment for another grind, or replacement of old grinding elements by new. The invention is especially applicable to power driven mills, such as the-fiat disc type, used by Wholesale and largeretail roasters and grinders of coffee, who when they once determine a satisfactory or standard fitness of grind for a given blend or customer, desire to reproduce the same adjustment of the grinder at any time, without ut and try or guess methods, notwithground, and a manufacturer, desiring to conform to such standard grinds, consequently. requires mo" a precision of adjustment in his grinding mills, and an ability to accurately and quickly reset a machine for any desired one of the several standard grinds provided for. C

The invention of this application accomplishes the foregoing results by providing in combination with the present day notched, angularly adjustable hand wheel, an adjustable index plate lettered for standard grinds and so mounted and arranged as to enable any desired grind to be quickly reproduced at will. In further combina tion, is a novel form of double latch cooperating with the notched wheel, so that intermediate standards can be obtained, if desired, thus doubling the number of standard grinds obtainable.

lln the accompanying drawings:

Fig. 1 is a longitudinal section through a mill embodying the present invention,

Fig. 2 is an end view of the scale and latching device,

Fig. 3 is a side view of the device of Fig.

Fig. 4 is a to view of the devices shown L in Figs. 2 and 3.

standing change of adjustment for other a For the purposes of illustration this infineness, (ii-disassembling to sharpen discs, clean the machine, or replace olddiscs by new. In mills heretofore devised, while it has been possible to obtain the desired adjustment for any given fineness of grind, exact reproduction thereof after disassembling of the machine or wear of the discs, has not been definitely and easily possible even with the use of notched distance adjusting screws and a latch to engage in the notches. Numbering of the notches or adjustment of the notched hand Wheel on the shaft is not sufficient, because of variation in discs. and Wear of threads, bearings, and discs. The best that could heretofore be done has been to cut'and try with more or less approximation to repetition of a previous grinddepending on the care of the operator and his ability to tell by eye how close a grind from a new ad'ustmcnt is to a previous or desired standar grind. Moreover, in the cofi'ee trade particularly, there is an increasing tendency to establish definiteness in the fineness of grinding by the use of reference samples of worl previously vention has been embodied in a grinding mill of the customary type illustrated wherein the pedestal 10 supports the mill which comprises the feed hopper 11 and rotatable spindle mounted in bearings 13 and 14 and driven by the pulley15, or other sourccof power. Below the feed hopper is a screw conveyor 16 attached to the shaft which moves the fed in material towards the grinding elements 17 and 19, the former of which is stationary and bolted, or other- 7 wise secured to the stationary housing 18, while the-latter, or rotatable grinding element 19 is adjnstably secured to the spindle 12oby the set screw 20. A threaded member 21 engages a thrust block 22 for moving the spindle 12 against the action of the compression spring 25 contained between the clearance spring. collar 23 and the bearing 14. The spring 25 is normally under compression and tends to force the spindle 12 against the thrust block andinto co-operation with the threaded member 21 which controls the spacing between the grinding elements 17, and 19,- and therefore controls the grade of product, fine or coarse, as desired. J The clearance spring collar 23 is secured to the spindle 12-by aset screw 24:, or other convenient means. 1 i

A spring in co-operation with the stationary housing 18, and the yieldable frame or housing 26 enables the rotatable grinding index is next clamped in its adjusted position by the screw 33. If the hand wheel is element 19, spindle 12, and housing 26 to be then turned until a desired mark, A, B, C, all moved to the left in Fig. 1, if a piece of etc., is opposite the latch 29, engaging the iron or other hard substance of large size latch sets the millso it will accurately progets wedged in between the grinding eleduce the corresponding grind, and it will ments l7 and 19; with the result that the also be seen that this ability of the mill to spacing between these elements enlarges unobtain the desired grind is independent of til the obstruction has passed through, the adjustment of the rotary grinding disc 15 'whereby mutilation of the grin-ding elements 19 on the spindle 12 and may be made indeis guarded against. The-hand wheel 27 conpendent of the gradual wear which takes trols the adjustment of the threaded memplace in any machine. g ber 21 and this hand wheel is shown in Figs. Among the advantages of this invention 2, 3 and l as being provided with a plurality may be enumerated the facility to obtain the 20 of teeth'28 on its periphery and secured to desired grade of product without the necesthe threaded member 21 by the set screw 27*, sity for cutandtrymethods, and the ability or other convenient means. Pivoted to the to obtain such desired grade with-out referframe or housing 26 by the pin is a latch ence to the wear in the machine, or the ad 29 for locking the hand wheel 27 in adjusted ,justment ofthe grinding disc on the spindle.

position, and adapted to fit in between the By means of this invention an operator teeth 28 without any lost motion, so as to using a plurality of mills can set them up hold the wheel'27 in accurate adjustment. alike, or such an operator could set new A. spring 31, arranged between the head of machines to produce the same grind as the pin 30 and the latch 29, may provide, the old machines, and could reset theold ones 30 necessary friction to retain the latch in to compensate for wear. Another advaneither of its positions without danger of its tage is that-this invention may be embodied becoming displaced. A thumb screw 33 and-applied to old machines whereby they clamps the scale or index plate 32 firmly may be calibrated to indicate the desired against the hand wheel 27 to hold this plate grade of product with accuracy and without in adjusted position. Letters 34 or other the necessity for test runs. The invention is appropriatejndicating symbols are placed not limited to mills of the type shown but on the index plate for the purpose of desig- -may also be embodied in machines having nating the grade of coarse or fine product cone type of grinding elements, and those obtained when the latch 0r pointer 29 is beof other than disc illustrated.

side a particular letter. Pivoted at 36 to We claim:

the first latch is a second latch 35 of in- 1. In a mill, the combination with relaverted U-shape having the sides of the U t-ively movable grinding elements, of means longer than the depth of the latch so that for adjusting the separation of said elewhen latch 29 goes over a tooth 28 instead of ments, -means for locking the adjusting between the teeth, the second latch 35 is means, a relatively movable scale and adapted to span the first latch and without pointer for indicating contact relation belost motion fit on opposite sides of the tooth tween said elements, and a plurality ofover which the first latch is held. 111 this separations thereof, and means for adjust way an increasednumber of grades of proding the relation between said scale and not is obtainable. pointer to indicate contact -between said In operation-the machine is assembled and elements whereby a definite separation of i the hand wheel and threaded member moved said grinding elements may be produced to force the spindle 12 to the rightuntil the regardless of wear." grinding discs 17 and 19 are in a contacting 2. In a mill, the combination with a staposition, where they have a minimum grindtionary grinding element, of a movable ing clearance. The hand wheel 27 is then grinding element, mechanism including a adjusted by means of its set screw 27*, until toothed wheel for adjusting at least one of the latch 29 is directly between a pair of such elements to control-their separation, a teeth to properlyengage and lock the hand frame therefor, a latch secured to said frame wheel, or instead the wheel 27 may be adto engage said toothed Wheel and lock the justed so that the channel shaped or inverted same to. operatively maintain said elements U latch 35 is in proper engagement with the in adjusted position, a scale secured to the wheel when the discs are in such position of toothed wheel and provided with a mark to w minimum grinding clearance. After the indicate a contacting position of said elehand wheel 27 has been locked in its admpnts, and also having other marks to indimamas cate difl'erent separations of said elements, said latch serving as a pointer for the scale and being relatively fixed, and an adjusting means for the scale whereby it may be moved to indicate said contacting position of the elements regardless of their wear and adjustment.

3. In a mill, the combination with a stationary grinding element, of a movable grinding element, mechanism including a toothed wheel for adjusting at least one of such elements to control their separation, a frame'therefor, a latch secured to said frame to engage said toothed Wheel and lock the same to operatively maintain said elements in adjusted position, a scale secured to the toothed wheel and provided with a mark to indicate a contacting position of said elements, and also having other marks to indicate difi'erent separations of said elements, said latch serving as a pointer for the scale and being relatively fixed, means for adjusting said toothed wheel relative to the grinding element controlled thereby, and an adjusting means'for said scale whereby it may be moved to indicate said contacting position of the elements and predetermine the grade of product regardless of wear and adjustment of the elements.

4. In a mill, the combination with a sta tionary grinding element, of a movable grinding element, mechanism including a toothed wheel for adjusting at least one of such elements to control their separation, a frame therefor, a latch secured to said frame to engage said toothed wheel and lock the same to operatively maintain said elements in adjusted osition, a scale secured to the toothed whee? and provided with a mark to indicate a contacting position of said elements, andalso having other marks to indi- I cate diflerent separations of said elements, said latch serving as a pointer for the scale and being relatively fixed, another locking means for the toothed wheel for cooperation therewith when the latch is over a tooth and cannot lock the wheel, and an adjustin means for the scale whereby it may be move adapted to fit between the teeth and lock said means when the first latch is over a tooth: 4

6. In a-mill, the combination with a stationary grinding element, of a rotary grindi'ng element co-operating therewith, a spindle on which said rotary element is removably mounted, means for axially moving said shaft to adjust said rotary element and con trol the grade of the product, a scale carried by said shaft moving means, a latch to lock said spindle moving means, and means whereby said scale may be adjusted to indicate the separation between said elements and the grade of product independently of the position of said rotary element on said 7 spindle.

Signed at New York, in the county of New York and State of New York, this 11th day of September, A. D. 1923.

a WILLIAM G. BURNS.

" GEORGE C. HER-Z. 

